function $(id) {
	return typeof id==='string' ? document.getElementById(id) : id;
}

window.onload = function() {
	//	获取鼠标滑过或点击的标签和要切换内容的元素
	var lis = $('notice-tit').getElementsByTagName('li'),
		divs = $('notice-con').getElementsByTagName('div');
	if(lis.length != divs.length)
		return;
	for (var i = 0; i < lis.length; i++) {
		lis[i].id = i;
		lis[i].onmouseover = function() {
			for (var j = 0; j < lis.length; j++) {
				lis[j].className = '';
				divs[j].style.display = 'none';
			}
			this.className = 'select';
			divs[this.id].style.display = 'block';
		}
	}
}